Midterm 1 Flashcards
(70 cards)
1
Q
What is Ecology?
A
It depends who you ask..
- the study of relationships between organisms and their environment
- Study of interactions that determine the distribution and abundance or organisms
- study of ecosystems, considers flow of biomass and energy
2
Q
What is the scientific method?
A
Approach where ecologists explore relationships between organisms&environment
- formulate and test hypotheses through observation, experiment and modelling
- we are testing things, never proving
3
Q
What are the 4 basic steps to the Hypothetico-Deductive Method? (Applied scientific method)
A
- Observe&describe phenomena- induction(observe a correlation and derive rules from it)
- Formulate a research hypothesis or multiple-deduction
- Make predictions about other facts that should be true if the research hypothesis is true
- Test these predictions experimentally( test reliability of R.H.)
4
Q
What is a research hypothesis?
A
Idea or possible explanation for some phenomenon
5
Q
What is a statistical hypothesis?
A
Test of a prediction from the research hypothesis
- relies on construction of null and alternate hypotheses
- allow you to determine whether your prediction is likely to be correct or incorrect
6
Q
Why can’t you except a null hypothesis ?
A
-you can reject it or fail to reject it but can never accept it because there’s no possible way the two sets of samples can be the absolute same(you’d have to test every sample possible)
7
Q
What is a mensurative study?
A
Some aspect of an organism, population or community is measured without manipulation
Ex. Density/plant size may be measured along a gradient of moisture
-quadrat sampling
8
Q
What are two important considerations when taking samples?
A
- samples must be independent
- samples must be randomly chosen
9
Q
Advantages and disadvantages to systematic sampling
A
- well spaced, representative, usually works okay
- samples are not independent
- not statistically valid
10
Q
Advantages/disadvantages to random sampling
A
- independent and statistically valid👍🏼
- potentially biased if samples are clumped👎🏼
- can generate inaccurate estimates if there is an environmental gradient involved 👎🏼
- probably fine if a significantly large number of samples are chosen
11
Q
A/D to stratified random sampling? (Random sampling with restriction on spacing)
A
- independent and statistically valid👍🏼
- representative👍🏼
- avoids problems with possible clumping of samples👍🏼
- a bit more work👎🏼
12
Q
What are manipulative experiments?
A
Aim to understand an excologicsl phenomenon by manipulating a particular factor and comparing the response of organisms or a community to an unmanipulated control
-can have multiple manipulations
13
Q
How can you figure out what unit size you should use for data collection?
A
- larger/rarer things need larger units
- can test this by taking progressively larger samples and seeing where densities or diversity level off
- beware of edge effect
14
Q
What is accuracy ?
A
Closeness of a measured value to its true value
-always strive for accuracy and avoid bias
15
Q
What’s precision?
A
Closeness of measured values to each other
16
Q
What is natural history?
A
- provides foundation for modern ecology and conservation biology
- study of how organisms are influenced by a range of factors within their environment
- often developed through informal observations and local knowledge
17
Q
What are terrestrial biomes?
A
- Large scale classification of terrestrial habitats
- distinguished primarily by their predominant plant species
18
Q
What are the 3 air circulation cells on each side of the equator?
A
- Polar cell-subtropical and polar air masses meet, creating a moist temperate climate
- Ferrel Cell-dry descending air absorbs moisture, forming deserts
- Hadley Cell-rising air at the equator is associated with a moist tropical climate
19
Q
What is the Coriolis effect?
A
- winds don’t simply move air north/south but are deflected
- apparent deflection to the right in the northern hemisphere and to the left in the Southern Hemisphere
20
Q
What is climate determined by?
A
Average precipitation and temperature
21
Q
What is precipitation and temperature influenced by?
A
- air currents
- latitude
- ocean currents
- topography(mountains/hills vs. flat)
- sunlight
- soil conditions
- results in different biomes with different organisms
22
Q
Describe Tundra biome
A
- dry/not much rain
- cold, short summers
- not a desert(because it’s not hot)
- anything that grows is small/short/tough and slow growing (mosses/grasses)
- supports number of large native mammals
23
Q
Describe Boreal forest(Taiga)
A
- long winters, short summers, huge temp range
- moderate rain
- soil is variable-some acidic, some highly fertile
- moss and bogs present
- dominated by evergreen conifers
- can have many animal taxa
- *disturbance driven ecosystem(ex, natural forest fires-can be good for some sp.)
- dense canopy cover(not a lot of ground vegetation)
- vulnerable to climate change effecting biodiversity
24
Q
Describe the temperate forest
A
- moderate temp, wide range of precipitation but no evidence of drought(blue rain line always over red temp line)
- fertile soils
- have understory of plants because canopy isn’t as thick(more then one type of tree)
- massive trees can have large amounts of carbon or biomass
- *humans have destroyed and built on many temperate forests (very reduced ecosystem)
- range of animals present
25
Describe temperate grassland
- globally widespread
- less precipitation and more dry compared to temperate forest
- droughts can be persistent
- most (herbaceous)plant biomass is underground(protected by grass fires)
- supports large herds of herbivores
- *biome is endangered(constantly harvesting on soil has reduced organic matter of soil)
26
Describe desert
- *dry but not necessarily hot(red line usually over blue line)
- *high evaporation/low precipitation
- not much soil-mostly sand&rock
- sparse vegetation
- animal abundance low but may be high in diversity
- *animals acquire many strategies to deal with dryness-light coloured/concentrated fat
- desertification is increasing due to climate change
27
Describe tropical rain forest
- close to equator
- *warm&wet year round
- annual rainfall
- can be lush but soils are nutrient poor, acidic (rain washes nutrients away)
- *exceptional diversity of plants&animals
- *human dependance and exploitation is extreme (ex.drugs) we cut down many rainforests(lost huge proportion)
- shallow root trees dominate
28
Diverse set of ecosystems in aquatic environment, name some
| -what are the challenge differences?
- oceans(deep sea and near shore)
- intertidal zones
- marshes and swamps
- rivers
- lakes
- peatlands
* entirely different set of challenges for aquatic environment than terrestrial
- temp is less challenging but harder to get O2
- don't have to deal with gravity(swimming)
29
What is the hydrological cycle?
-Exchange of water among "reservoirs"
30
What are the 3 ocean zones?
1. Intertidal zone: shallow shoreline; tidal influence, variable depending on location (area between high and low tides lines)
2. Neritic zone: coast to margin of continental shelf
3. oceanic zone: beyond continental shelf; divided into vertical zones(based on light&temp variation)
31
Define benthic and pelagic
Benthic: habitat on the bottom
Pelagic: habitat off the bottom
32
What are the abiotic factors influencing ocean communities
-light: not much absorbed, most is reflected back(esp. blue)
80% of solar energy is absorbed in the first 10 m
-temperature: warm water floats, generates thermal stratification and thermoclines.
Temp is more stable than lakes/land water because it takes a lot to change temperature of something so large
-water movements: Wide driven surface currents, facilitates nutrient/oxygen mixing and depth circulation
-Salinity: Very stable but varies slightly depending on ratio of precipitation to evaporation (34-36.5 ppt)
-Oxygen: Highest conc. near surface due to photosynthesizing plants and decreases with depth down to ~1000m then increases again(fewer organisms use O2 deep below)
33
What are the biotic aspects of ocean communities
- photic zone is very important
- Phytoplankton is the base of the food web, supports all life (1/4 of all PS in biosphere)
- human influences are increasing – overfishing, oil extraction, garbage
- deep water organisms are nourished by ocean mixing and chemosynthesis
34
What are the two shallow marine waters?
1. kelp forests in temperate areas(can extend 25 m above sea floor)
2. Corals near the equator(can form as barriers, fringes, or atolls – in all cases offer a complex habitat supporting great species diversity)
35
What Abiotic Factors influence shallow marine waters? (Kelp&coral)
(TOWLS)
- light: limits kelp growth and coral reef development. Penetration depth varies from 10-100m (merky water=less light penetration)
- Temp: corals are sensitive to heat(~23-25°) whereas kelp have a wider temp range that they can tolerate(~10-20°)
- Water movements: currents remove wastes, deliver oxygen&nutrients, productively influenced by flushing
- Salinity: Corals require stable salinity whereas kelps are more tolerate to variation
- Oxygen: well oxygenated (not deep water so not a huge problem)
36
What are the biotic aspects of shallow marine communities ?
- among the most productive and diverse ecosystems on earth
- both are vulnerable to disruption from uncontrolled predation, human disturbance/exploitation(kelp harvesting) and climate change
- kelp recovers more rapidly/better than corals
- sea otters protect/sustain kelp by eating sea urchins which destroy the kelp forests
- corals can become bleached if water gets too warm(colour-giving dinoflagellates/algae leave turning coral white)
37
Benefits to kelp forests?
- provide home for many fish(provides food for us to eat)
- defends coastlines against storms and cyclones
- slow down global warming(stores carbon)
38
What is intertidal zonation?
Zonation= region of intertidal zone that organisms live in
- duration of air exposure strongly influences species composition
- also depends on how rocky/sheltered IT zone is
39
Abiotic factors influencing intertidal zones ?
- Temp: greatly variable, especially when exposed to air and when in tide pools
- Oxygen: not typically limiting
- Water movements: usually semi-diurnal (happen twice a day) and magnitude varies
- light: depends on air exposure and water turbidity
- Salinity: highly variable (especially in tide pools)
40
What are some biotic aspects of intertidal zones?
- intertidal taxa are well adapted to withstand thermal and desiccation stresses
- on rocky shores, many organisms(ex. Barnacles,mussels) attach to hard surfaces, on soft shores, most are burrowers
- competition and predation play important roles in structuring communities
41
What are salt marshes?
Transition zones from sea water to land, concentrated along low-lying coast in sandy/muddy areas
- periodically flooded/inundated as channels fill at high tide
- where rivers meet sea
42
What are estuaries? And salt pans?
Estuaries- Found where rivers flow into the sea-salt and fresh water merge
Salt pans- small basins in marshes that retain water when the tide recedes
43
Abiotic factors influencing salt marshes?
Temp&light: both highly variable due to tidal influence (like intertidal zone) and due to solar heating of salt pans
water movement:tidal influence can extend up to 200 km
Salinity: depends on tidal inflow and evaporation rates. Less Salty water tends to float- mixing of river and ocean water
Oxygen: highly variable (from very depleted to supersaturated)
44
What are some biotic aspects of salt marshes
- plant diversity is limited but the plants there are in abundance and there is high primary production
- animals can withstand environmental fluctuations
- very important nursery habitat for fish and critical environment for many birds
- humans have dived marshes, built causeways and polluted many salt marshes. Restoration is now underway in some areas
45
What are river basins?
Areas that are drained by a network of rivers and streams (ex. Mississippi River basin)
46
Define the following zones: riparian, benthic, hyporheic and phreatic
```
Riparian: outside the active channel, the riparian zone is the transition between the aquatic environment of the river and the upland
terrestrial environment (banks or river edge)
```
Benthic: includes the surface of the bottom substrate (bottom of river) under water column
Hyporheic:below benthic zone-transition between areas of surface water flow and ground water
Phreatic: area containing ground water under the hyporheic zone
47
Abiotic factors influencing rivers/streams
Temp: typically 0-30°, relative to terrestrial conditions
Oxygen: varies inversely with temp, flow rate also important
Water movements: key feature-varies from almost still to rapids. More water in system=faster flow directionality- upstream processes affect downstream environment
Light: light penetration depends on riparian shading(trees), presence of organic matter and turbulence
Salinity: depends on materials leaching from surrounding environment (typically lower in tropics and high in deserts)
48
What is the river continuum concept?
A model the predicts change in physical structure, dominant organisms and ecosystem processes along the length of temperate rivers
-what happens at the top of the river(narrow part) influences the bottom of the river(wider part)
49
Biotic aspects of rivers
- greater diversity in tropical than temperate rivers
- species composition changes as we move downstream
- sediment influences community-soft vs rocky (like intertidal zone)
- humans are very dependent on rivers-irrigation, transportation, energy, food, waste disposal
- we have poisoned them, damned them, introduced species,..... remediation is a major ecological goal
50
Describe the zones of lake structure
Littoral zone: shallowest waters along lake shore, rooted aquatic plants may grow(primary production/growth/sunlight)
Limnetic zone:open lake(divided vertically into 3 main depth zones) below
Epilimnion: upper warm surface layers of lake
Metalimnion: aka thermocline- temp changes substantially with depth
Hypolimnion: below thermocline- cold dark waters
51
Abiotic factors influencing lakes
T: thermal stratification is common. In winter some lakes freeze solidly or have surface ice
O: inversely related to biological production:
Oligotrophic- low biological production and well oxygenated
Eutrophic- high biological production and oxygen depleted
WM: wind driven mixing of the water column(limited to thermal stratification or freezing)
L: light penetration depends on absorption which is affected by water chemistry, biological activity and depth
S: more variable than oceans, usually very low but can be high in salt lakes
52
Biotic aspects of lakes (compare oligotrophic and eutrophic, and human influences p)
- oligotrophic lake: low nutrients, cool temps, high 02 conc., low levels of primary production, thermocline, deep bottom
- eutrophic: warm temps, low 02, high nutrient availability, high level of primary production, shallow bottom
- VERY negative- pollution, agriculture runoff, toxic waste, species introduction(alters community structure and has neg affect on native species. Ex. Lamprey)
53
Describe peatlands
- consists of bogs and fens
- low decomposition( over thousands of years) of mosses and sledges leads to build up of peat
- bogs are fed by precipitation only-has vascular plant growth
- fens are flat and have standing water
54
Abiotic factors influencing peatlands
T: increased temp can lead to increased decomposition and water evaporation rates and decrease peatland development
-usually cold
O: not much oxygen- limits vascular plants (coniferous plants found here)
WM: still/ stable waters are needed
L: can vary widely depending on presence of vegetation above. Light penetration through water is limited
S: not important
pH: critical- very low pH/acidic in bogs and fens
55
Biotic aspects of peatlands?
- lots of coniferous plants(meet N2 needs)
Ex. Pitcher plant
-not a lot of animal diversity(some insects but not many big animals)
-humans are hard on peatlands too- peat extraction is common and highly destructive (sustainable harvest not possible)
-climate change posses serious challenges
(If temp gets warmer/ water dries up, pest will break down and release a lot of carbon into the atmosphere)
56
What is the law of tolerance?
-distribution and abundance of species depends on deviation between local and optimal conditions for species
-shape of response curve may not always be normal and can vary
-an individuals performance can be limited by environmental conditions
Ex. Most sp. can perform best in narrow temp range but some can acclimate better than other(some can't adjust and won't have a good fitness level)
57
What are adaptations
- evolutionary context: traits that are assumed to be the result of natural selection
- heritable trait that maintains or increases the fitness of an individual under a given set of conditions
58
What is fitness
The relative contribution of an individual in a population towards future generations
- higher fitness=more babies (spread your genes throughout population)
- contributes traits to future generations
59
What are ecotypes?
- individuals with genetically determined differences between populations within a species that reflect local matches between the organism and its environment
(Can be many different types of adaptations within a species-local adaptations)
60
What is plasticity?
Adaptation within an organisms lifetime
(Capacity to make an individual change, *not an evolutionary adaptation)
-ways that animals can cope with stress(physiological response)in environmental conditions
-can be seasonal or short term or longer term
Ex. Some grasshoppers change pigmentation on wings to lighter colour when it gets hotter
61
Why is regulating temperature critical for organism ?
Balancing heat gain against heat loss is critical for ; development, growth, life cycle, sex determinism, enzyme activities, metabolic regulation
- there are multiple pathways for heat exchange between organisms and environment
62
Define poikilotherms
Body temp varies directly with environmental temperature
- don't have to work as hard to maintain body temp because it changes with external temperature
- have to maintain enzymes
- usually cold blooded (snakes/frogs)
- metabolic rates mostly increase with temperature
63
Define homeotherms
Maintain a relatively constant internal temp
- this is expensive (have to work hard to maintain body temp
- don't have to have multiple enzymes
- most mammals&birds
- metabolic rates remain constant over a limited temperature range
64
Define endothermy
Rely heavily on metabolic energy to heat body or critical organs
-have to heat or cool yourself
-usually mammals&birds
Ex. Rabbit -sweating or raise hair or shivering
-warm blooded
-have to eat a lot to keep themselves warm
-thick coat to keep heat in
-big ears let out heat
65
Define ectothermy
Rely mainly on external energy sources(sun) and behaviour to regulate internal temp
-cold blooded
-can go a long time without eating because they just go into the sun
Ex. Lizard & turtles & alligators & butterfly
-move in shade
-most plants
66
Diapause ?
Complete shutdown annually in life cycle
67
How do ectothermic animals regulate body temperature (external energy)
- sun bask or go in shade
- dark colour if called, light colour if hot
- they might adjust size or shape – being tiny is hard to stay warm and vice versa
68
How do you endothermic animals regulate body temperature(use metabolic heat)
-have more challenges cooling off, so require additional adaptations to dissipate metabolic heat (panting, sweating, large extremities such as large ears)
69
Strategies to cope with cold
Death, migration, resistance( hibernation-reduce metabolic rate during cold, fur/fat, seek shelter, allow yourself to freeze, acclimate)
70
What is Torpor
Short term productions to reduce metabolic rate. Hummingbirds do this because their body is small
Drop body temperature usually overnight
-if a bird doesn't have enough nectar, there is more likely to go into torpor at night, but won't do it unless it has to
